1. Field of the Invention
The present invention generally relates to a bicycle front derailleur with angle adjustment. More specifically, the present invention relates to a bicycle front derailleur with an adjustment mechanism that provides angular adjustment of a chain cage of the front derailleur with respect to the bicycle frame.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle front derailleur.
Generally speaking, the front derailleur is typically secured to the seat tube of the bicycle frame or the bottom bracket. Basically, a front derailleur includes a base (fixed) member non-movably secured to a bicycle frame, a movable member supported to be movable relative to the base member and a chain guide. Typically, the base member is a tubular clamping member that is secured to the seat tube. The movable member typically is formed of a pair of pivotal links that form a four-bar linkage with the base member and the chain guide. The chain guide typically has chain cage with a pair of cage plates for contacting and moving a chain between front sprockets of a bicycle drive train. The chain guide is usually biased in a given direction relative to the base member by a spring. The chain guide is usually moved relative to the base member by pulling and/or releasing a shifter control cable that is coupled between a shifter and the front derailleur. The control cable is often connected to one of the pivotal links to apply a torque thereto in order to move the chain guide between an extended position and a retracted position. More recently, front derailleurs have been developed the use other types of arrangements for the movable member, e.g. an electric motor arrangement, a hydraulic arrangement, etc.
As mentioned above, the bicycle front derailleur typically has a base member mounted to the seat tube of the bicycle frame. Generally, the chain cage of the front derailleur has a fixed angular orientation with respect to the base member and the bicycle frame. However, many different bicycle frames are in use today with different configurations of the seat tube. Some bicycle frames have their seat tubes slightly inclined from vertical, while other frames have their seat tubes inclined at a greater angle with respect to vertical. Thus, a problem exists with typical bicycle front derailleurs in that the angular orientation of the chain cage is fixed with respect to the base member. Specifically, since the angular orientation of the chain cage is fixed relative to the base member for most bicycle front derailleurs, the bicycle front derailleur might not be able to be installed at the optimal orientation for all bicycle frames that are currently available. Hence, several different configurations of bicycle front derailleurs are necessary to accommodate the various bicycle frame configurations that are currently available.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved bicycle front derailleur that can be used on a variety of different bicycle frames. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.